Irritating bearing suppliers

[katou]

Hi, I hate to post and ask for help for something so simple, but I'm having a devil of a time figuring this out.

I am building a small transmission very similar to Mud's

http://endless-sphere.com/forums/viewtopic.php?f=28&t=14734

And I can't seem to find cheap bearings local to me. They either want to sell me Chinese bearings for 6$ each that have a 2000rpm rating, or Japanese bearings for 15$.
Apparently 1/2" ID is an oddball size? I said, okay, so 15mm is okay, how much for a shaft? Oh, we don't sell that, most people don't, it's hard to get.

WTF?

VXB has a plethora of bearings of course, but then I can choose whatever price level I want. Too much choice. Can someone help me pick the right ones?

I need rpm up to 10,000 or so, nothing NASA certified, but not crap either. I don't want to go online, I'd prefer local, but it looks pretty much impossible to do that. How do these companies stay in business?

Katou

 

[Lock]

I spent a little time trying to understand bearings:
http://endless-sphere.com/forums/viewtopic.php?f=2&t=7107

...beyond ABEC numbers the sense seemed to be that a mfgr w/a good reputation was v.important. My gut tells me that for the trouble and expense of replacing bearings and given their function it may be money well spent to get the best (most expensive?) that you can afford...

Cheers
Lock

 

[Thud]

K,
Here are some bearings I have used with success in identical applications for your use.
I use VXB almost exclusivly these days. A phone call & I can order odd sizes they don't have on the web.
Mostly of Chineese origin lately but the quality is very servicable.

Flanged with a .5" ID. Not sealed, but unless your exposed to dirt riding exclusivly these are good.
http://www.vxb.com/page/bearings/PROD/1-2inch/Kit7578

Standard. I think this is what Matt uses on his drives & it is what I am putting in my 2 speed units:
http://www.vxb.com/page/bearings/PROD/1-2inch/Kit7527

In bicycle applications you will have to work very hard to "fail" either of these if set up & installed properly.

I used these in my prototype trannynot really recomending, these are fragile)
http://www.vxb.com/page/bearings/PROD/1-2inch/kit821
these work really well also but are a b##ch to get set up proper. I tried .001 press fit & they bound up really bad. Worked with net slip fit & locktite 271 (red) to mount the bearings (broke 3 units to determine best fit )
Hope that helps.

 

[katou]

Thanks a ton both of you.

This is actually of more help that you might think, although I have wait to install them, I can buy the tooling to install them just knowing the OD. No matter which one I get, they are all 1-1/8"

Why did you get those teflon sealed bearings Thud? I guess the pain in the ass of installation wasn't worth it. Do they roll nicer or something? They are really thin!

Katou

 

[swbluto]

Hi, I hate to post and ask for help for something so simple, but I'm having a devil of a time figuring this out.

Yeah, this is a tough nut to crack. The most experienced one, LFP, seems to suggest if you want quality you have to buy the most expensive: fully ceramic. However, it's a bit hard to swallow that a good small bearing must cost > $50! Surely there are some "good" bearings that aren't crap, either? I've tried VXB chrome shielded bearings but they seem to eventually fail in my application within a short amount of time, so I'm not really convinced they're the "good stuff" of bearings. So, it seems like there should be some "good quality" middle ground but yet I haven't found it.

Yeah, they may be "serviceable" but hell if I know how.

 

[Thud]

Glad it helped K,

Why did you get those teflon sealed bearings Thud? I guess the pain in the ass of installation wasn't worth it. Do they roll nicer or something? They are really thin!

The teflon seal is usless IMO. its just a very thin/light sheild to keep dirt out. The balls & race are standard steel. I bought them for their tiny size. They fit into 1/4"t stock. But they are very fragile & if a few grains of sand get in, they will be fragged nearly instantly.

VXB is just a supplier/importer. They have bearings for most applications.
I have had new industrial routers that would eat quality bearings regularly (poor armature ballance & alignment issues). Add-bearing instalation requires a light touch for some of the tiny ball bearings we use in RC motors. (& yes some bearings are just JUNK from the mfr's.)

I remember the 1st set of ceramic bearings A buddy sprung for (12th scale carpet rc car racing) Big $$ zero drag...car was undeniable faster & ran dead silent. He nerfed a wall & shatered all the balls in them tiny housings.....$$$ sprinkled in the chicane after 5 minutes of fun.

 

[recumpence]

I use 1/2 inch ID, 1 and 1/8 inch OD flanged bearings. They cost me $2 each. If you want some, I can send them to you.

Matt

 

[katou]

That is very generous Matt, I will consider it.

The only reason I don't jump on it, is that I'm trying to learn how to build machines from scratch, and if I get the bearings from you, I do not have a source for the future. As you know, a big part of building anything is getting the right suppliers and finding the right hardware. That's what I need to do. I want to give it a shot on my own, so we'll see.

Katou

 

[katou]

Damn, yours are even flanged.

Katou

 

[katou]

I have done it. At long last. How lame that this feels like an accomplishment. Oh well, I figure it's good to celebrate the little successes, otherwise I might not have anything to celebrate at all!

I chose a bearing from VXB that comes with a 20,000 rpm rating.

http://www.vxb.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=bearings&Product_Code=kit958&Category_Code=1-2inch

None of the bearings come with any kind of comparative quality ratings - what's up with that? So I figured that a bearing that could get up to 20krpm had to be some kind of quality assurance.

I am very surprised that bearings are not spec'd a little more thoroughly than they are. I can get Gr 5 bolts, and they're spec'd very accurately. I can buy specific alloys with guaranteed composition, but bearings seem to have very few standards. I would have thought that they would come with static and dynamic friction ratings, as well as max rpm and temperature ranges at least.

Oh well, in the final product, I probably wouldn't be able to tell anyway. Thanks for the help everyone.

Katou